REMOVING OR PREVENTING DRY ETCH-INDUCED DAMAGE IN Al/In/GaN FILMS BY PHOTOELECTROCHEMICAL ETCHING

A method for removing dry-etch damage from a substrate surface, the method comprising:

• providing a substrate comprising an n-type Al/In/GaN semiconductor material, a surface of the substrate having dry-etch damage thereon;
• immersing the surface of the substrate in an electrolyte solution;
• and
• illuminating the surface with above bandgap light having a wavelength that generates electron-hole pairs in the n-type Al/In/GaN semiconductor material, thereby photoelectrochemically etching the surface to remove at least a portion of the dry-etch damage.

A method for forming a p-n junction, the method comprising:

• providing a substrate comprising an n-type GaN semiconductor material;
• dry-etching a surface of the substrate to form a trench therein and causing dry-etch damage to remain on the surface;
• immersing the surface of the substrate in an electrolyte solution;
• illuminating the surface with above bandgap light having a wavelength that generates electron-hole pairs in the n-type GaN semiconductor material, thereby photoelectrochemically etching the surface to remove at least a portion of the dry-etch damage;
• and
• regrowing a p-type GaN semiconductor on the photoelectrochemically etched surface to form a p-n junction.